My first thought was: why would he want to do that? Then I realized that I have seen a rare style in which a brace or bracket alone groups the staves that form a system. And there might be other reasons.

This is possible in Finale by removing all left bar lines for all measures in the piece with the Measure Tool.

I want to be done with Finale too, but only if I can get better results and have greater control over all elements than I now have with Finale. I don't want to get involved in a project only to discover that there are roadblocks because I am trying to do things that the designers proscribed or didn't foresee.

John, exactly those same kinds of "roadblocks" exist in Finale as well, but you're used to them, both because Finale is old enough to contain features for every possible requirement and because you are used to the way the program works. It takes time to program every one of those features, which is very probably why Finale still can't, for example, do tremolos or beaming across barlines natively and requires either tedious manual workarounds or plug-ins to achieve those things. Dorico, as a young product, cannot provide the functionality every single checkbox in every single nested dialog in Finale (and I hope it never has to).

Robby, it would be possible in the future to prevent the systemic barline at the start of the system from drawing, but as I have said, there is a cost involved in adding every feature, and we have to weigh the relative priorities of thousands of competing requirements every day when deciding what to work on, so I can't promise when we will be able to address this.